Collar bar



FIG. 1 is a perspective view of a collar bar showing my new design in use;

FIG. 2 is another perspective view in closed position; and

FIG. 3 is a perspective view in open position.

The broken line showing of a tie and collar in FIG. 1 is for illustrative purposes only, and forms no part of the claimed design. 

The ornamental design for a collar bar, as shown and described. 